Radiotelephones generally refer to communications terminals which provide a wireless communications link to one or more other communications terminals. Radiotelephones may be used in a variety of different applications, including cellular telephone, land-mobile (e.g., police and fire departments), and satellite communications systems.
Radiotelephones and other communication devices are undergoing miniaturization. Indeed, many of the contemporary radiotelephone models are less than 11-12 centimeters in length. As a result, antennas that swivel or pivot from a stored position adjacent to the housing of a radiotelephone to a position extending outwardly from the housing are becoming increasingly attractive to radiotelephone manufacturers. Swivel antennas can achieve good radiation performance when in outwardly extended positions. Unfortunately, these swivel antennas can become severely de-tuned, and even rendered inoperable, because of impedance mismatching, when in a stored position adjacent the housing of a radiotelephone. As a result, radiotelephones may not be operable when a swivel antenna is in a stored position.
Impedance mismatching may occur due to the close proximity of an antenna to a radiotelephone housing and/or to various ground planes within a radiotelephone. Impedance matching components and/or circuitry can be added to a radiotelephone to match the impedance of a swivel antenna when in a stored position. However, incorporating additional matching components and/or circuitry may be somewhat expensive and available space within radiotelephones may be somewhat limited.
It would be desirable for radiotelephones incorporating swivel antennas to be operable when the antenna is in a stored position. Accordingly, the reception of paging signals could be enhanced. In addition, to facilitate reducing costs associated with manufacturing radiotelephones, and to accommodate miniaturization, it would be desirable to utilize swivel antennas without requiring additional impedance matching components and/or circuitry.